New clinical study determines that close to half of patients who suffer a blood clot in their lung will experience exercise limitations at one year

A multi-centre clinical study, led by Dr. Susan Kahn at the Jewish General Hospital (JGH), determined that nearly half of the patients who suffer a pulmonary embolism (PE) -- a blood clot in the lung -- experience long term limitations to their capacity for physical activity and that this had a negative impact on their quality of life. This research, published in Chest, is the first to demonstrate that PE may have a lasting effect on patients.

"Our clinical experience told us that some patients who'd had a pulmonary embolism suffered from shortness of breath and chronic fatigue long after the PE had been treated and resolved," explained Dr. Kahn, who is founder and director of the Centre of Excellence in Thrombosis and Anticoagulation Care (CETAC) at the JGH, and an epidemiologist at the Lady Davis Institute at the JGH. "Our study revealed that 47% of participants showed a significant reduction in their physical stamina."

One-hundred patients were followed over the course of a year following treatment for PE. They answered quality of life questionnaires and participated in a number of physiological tests to measure their cardiopulmonary functions. All of the participants were generally healthy when they experienced their PE, so it was surprising that nearly half performed below 80% of their predicted peak oxygen uptake (a standard measure for cardiopulmonary exercise testing) one year later. These patients also scored lower in variables used to measure quality of life.

"One of the tests we use is to see how far a patient can walk in six minutes, which is a basic measure of mobility and stamina. When someone is limited in performing this test, it is really something that is interfering with their normal day-to-day functioning," said Dr. Kahn, a Professor of Medicine at McGill University, who is recognized as a world leader in research and treating patients with venous thromboembolism (VTE).

The underlying cause of the PE did not seem to be a predictor of whether a person may experience long-term repercussions. The study did reveal that men were three times more likely to have adverse effects, younger patients fared worse, as did more overweight patients and smokers.

Though further study is required, the outcome of this research suggests that patients with PE may benefit from some form of exercise rehabilitation as part of their recovery.

McGill University. "Long-term limitations imposed on patients with pulmonary embolism: New clinical study determines that close to half of patients who suffer a blood clot in their lung will experience exercise limitations at one year." ScienceDaily. ScienceDaily, 20 March 2017. www.sciencedaily.com/releases/2017/03/170320143820.htm.